1. Field of the Invention
Methods and apparatuses consistent with the present invention relate generally to a channel estimation in an Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system, and in particular, to low-complexity channel estimation for a block-type training sequence
2. Description of the Related Art
Generally, channel estimation is achieved based on the so-called training sequence, and the training sequence can have a block structure. The training sequence is equal in structure to the IEEE 802.11 training sequence. A simple channel estimation algorithm includes a Least-Square (LS) algorithm, and actually, the LS algorithm is very popularly used. As a well-known algorithm improved in performance from the LS algorithm, there is a Minimum-Mean-Square-Error (MMSE) algorithm. However, an increase in the complexity of the MMSE algorithm is very considerable in actual application. Characteristics of the two different channel estimation algorithms are as follows:                LS algorithm: low complexity but has normal performance.        MMSE algorithm: good performance but has very high complexity.        
Generally, because there is a tradeoff between the complexity and the performance as described above, a decrease in the complexity can considerably decrease the performance. Accordingly, there is a need for a channel estimation algorithm having low complexity and high performance for actual application. That is, there is a demand for a channel estimation algorithm which is higher in performance than the LS algorithm, and lower in complexity than the MMSE algorithm.